iPhone 7 Plus problems after battery replacement

After iPhone 7 Plus battery replacement, I am having trouble with the home button (and/or Taptic Engine), speakers, volume buttons, and microphone. These are non-functional. I have checked the connectors and reseated the Taptic Engine without improvement. All other functions appear intact with the use of the on-screen home button. However, the inability to communicate by phone (the calls still go through) leaves me without the primary function, not to mention I don’t want to go back to a world without Touch ID! I’m worried that I re-connected the battery out of sequence and damaged some of hardware.

Would this make sense given the constellation of problems?

Are there one or two hardware components that could potentially fix this problem?

Notably, the proprietary home button prevents third parties from addressing this and Apple will not accept iPhones for repair if ifixit (or other third party vendor) hardware is evident. Potential catch 22 if I cannot address this.